1. Field of the Invention
The present invention relates to equipment that analyzes cells, microorganisms, chromosomes, nucleic acids or the like in samples by use of biochemical reaction such as antigen-antibody reaction or nucleic acid hybridization, and to a biochemical treatment equipment system comprising a biochemical reaction cartridge used integrally with the equipment.
2. Related Background Art
A vast majority of analyzers for analyzing samples such as blood use an immunological method that utilizes antigen-antibody reaction or a method that utilizes nucleic acid hybridization. For example, the analyzers use a protein such as an antibody or an antigen specifically binding to a substance to be detected or a single-stranded nucleic acid as a probe, which is in turn immobilized on the surface of a solid phase such as fine particles, beads or glass plates and subjected to antigen-antibody reaction or nucleic acid hybridization with the substance to be detected. Then, a labeled substance having specific interaction, for example, a labeled antibody or antigen or a labeled nucleic acid, which carries a labeling material with high detection sensitivity such as enzymes, fluorescent materials or luminescent materials, is used to detect the presence or absence of the substance to be detected or quantify the substance to be detected, by detecting an antigen-antibody complex or a double-stranded nucleic acid.
For example, U.S. Pat. No. 5,445,934 discloses, as a modification of these techniques, a so-called DNA microarray where a large number of DNA (deoxyribonucleic acid) probes with a different base sequence from one another are arrayed on a substrate.
Alternatively, Anal. Biochem., 270 (1), p. 103-111, 1999 discloses a method of fabricating a protein array structurally similar to a DNA microarray, in which plural types of proteins are arranged on a membrane filter. As described above, the use of a DNA microarray, a protein array and so on has allowed the examination of a very large number of items at a time.
In various methods of sample analysis, a disposable biochemical reaction cartridge that internally performs necessary reaction is also proposed for the purpose of reducing contamination by samples, improving reaction efficiency, miniaturizing equipment, simplifying procedures, etc. For example, National Publication of International Patent Application No. H11-509094 discloses a biochemical reaction cartridge capable of extraction or amplification of DNA in a sample or reaction such as hybridization in the interior of the cartridge by arranging several chambers in the biochemical reaction cartridge containing a DNA microarray and moving a solution through differential pressure.
In general, a DNA microarray is installed in a biochemical reaction cartridge with the microarray bonded and fixed. The biochemical reaction cartridge is assembled in a clean room for preventing contamination. The biochemical reaction cartridge is composed of two plates with irregularities and the DNA microarray and has a hermetically sealed internal space.
It is necessary to accumulate reagents (solutions), for example, a first hemolytic agent containing EDTA destroying cell walls and a second hemolytic agent containing a protein denaturant such as a surfactant, in chambers in the biochemical reaction cartridge. These reagents may be accumulated in advance in a planned chamber site in one of the plates that form the biochemical reaction cartridge, followed by the assembly of the biochemical reaction cartridge; or otherwise, the reagents may be injected through an external syringe pump or vacuum pump into the biochemical reaction cartridge after the assembly of the biochemical reaction cartridge.
However, a surface facing the probe-forming surface of the DNA microarray installed in the biochemical reaction cartridge was always exposed to the outside air.
On the other hand, known methods of moving a solution in the interior of a biochemical reaction cartridge utilize gravity, capillary action and electrophoresis. In addition, there is disclosed a small micropump that can be placed in the interior of a biochemical reaction cartridge, including a micropump using a heating device (Japanese Patent No. 2832117), a micropump using a piezoelectric element (Japanese Patent Application Laid-Open No. 2000-274375) and a diaphragm pump (National Publication of International Patent Application No. H11-509094).